function AlienShip(){
	this.gameEngine = null;	
	this.parent = new GameObject();
		
	this.maxFuel = 200;
	this.currentFuel = 200;
	
	this.updatePosition = function(){
		var ax = 0;
		var ay = 0;				
		
		if(this.parent.xVelocity>0){
			if(ax>0){
				ax = Math.max(0,ax - this.parent.breakAcceleration);
			}				
			else if(ax<=0){
				ax -= this.parent.breakAcceleration;
			}										
		}
		else if(this.parent.xVelocity<0){
			if(ax>=0){
				ax +=this.parent.breakAcceleration;
			}				
			else if(ax<0){
				ax = Math.min(0,ax + this.parent.breakAcceleration);
			}						
		}
		
		if(this.parent.yVelocity>0){
			if(ay>0){
				ay = Math.max(0,ay - this.parent.breakAcceleration);
			}				
			else if(ay<=0){
				ay -= this.parent.breakAcceleration;
			}										
		}
		else if(this.parent.yVelocity<0){
			if(ay>=0){
				ay += this.parent.breakAcceleration;
			}				
			else if(ay<0){
				ay = Math.min(0,ay + this.parent.breakAcceleration);
			}					
		}				
		
		this.parent.x+=this.parent.xVelocity + ax/2;
		this.parent.y+=this.parent.yVelocity + ay/2;
		
		this.parent.xVelocity += ax;
		this.parent.yVelocity += ay;
	}
	this.updateRotation = function(){}
	
	this.update = function(){
		this.updatePosition();											
		this.updateRotation();
	}
	this.draw = function(){
		var ctx = this.gameEngine.canvasContext;		
		ctx.translate(this.parent.x,this.parent.y);
		ctx.rotate(this.parent.angle);
		
		ctx.strokeStyle="black";
		ctx.strokeRect(-10,-20,20,40);
		
		ctx.beginPath();
		ctx.arc(0,0,this.parent.collisionRadius,0,2*Math.PI,true);
		ctx.strokeStyle="green";
		//ctx.strokeRect(-10,-20,30,50);
		ctx.stroke();
		ctx.closePath();
				
	}
		
}